Operating characteristics of solar thermal electric integrated heating system for the oilfield single well tank in cold regions

The traditional heating method for oilfield single well tank (SWT) relies on gas or electric heating, which is associated with problems such as high energy consumption, substantial carbon emissions, and elevated operating costs. A novel solar thermal electric integrated heating system for the SWT is proposed to solve the above-mentioned problems, and the operating characteristics of the solar thermal electric integrated heating system for the SWT are explored. A TRNSYS-based simulation model is developed and validated against experimental data to quantify the dynamic energy performance of all system components across typical winter days and the full annual operating period. The results showed that during the winter solstice period, the energy supply proportion of the proposed system is 16% for phase change thermal storage tank (PCHT), 25% for evacuated tube collector (ETC) and 59% for electric heating rod (EHR). The power consumption of the EHR and the circulating pump (CP) are supplied by photovoltaic (PV), the power grid, and the battery, accounting for 3%, 67%, and 30%, respectively. The system guarantee rate reaches 89.17% during the four coldest winter months, with the SWT temperature consistently maintained above 40 °C; and the solar energy guarantee rate peaks at 73% in the highest-irradiance month. The annual energy supply to the system by the collector and the PV module is 862.4 kWh/m2 and 305.1 kWh/m2, respectively. These contributions allow the collector and the PV module to supply 39.5% of the thermal energy for the SWT and 15.1% of the electrical energy for the EHR. Furthermore, the economic and environmental evaluation reveals that the system reduces annual grid electricity consumption by nearly 80% compared to traditional electric heating. Despite the initial investment, it can achieve a dynamic discounted payback period of 5.22 years and cumulatively reduce carbon emissions by 1777 tons over its 20-year lifespan.